1. Field
Embodiments relate to a manipulator which is capable of avoiding collision with an obstacle, and a control method thereof.
2. Description of the Related Art
As robots have been developed, the necessity of cooperation between robots or between a robot and a human is emphasized in an industrial robot field as well as in an intelligent service robot field. In an industrial robot, a multi-joint manipulator is formed in the shape of human hand and arm to provide movements of the hand and arm. The multi-joint manipulator includes plural links connected to each other. Connection portions of the plural links are referred to as joints, and movement characteristics of the manipulator are determined according to the geometric relationship between the links and the joints.
The most basic manipulator has 6 degrees of freedom (DOFs) of interactive configuration to completely control spatial position and direction of a tool mounted at the tip of the manipulator. Another manipulator has an additional 1 DOF provided at an elbow in addition to 6 operating DOFs, such as a human arm. The manipulator having 6 operating DOFs does not have a redundant DOF, and thus does not avoid collusion with an obstacle only through an internal motion, i.e., a motion of an elbow. However, the manipulator having 1 redundant DOF in addition to 6 operating DOFs is capable of avoiding collision with an obstacle through a motion of an elbow. That is, the 7-axis manipulator is capable of avoiding collision with an obstacle using the redundant DOF without damaging continuity in an operation, or stopping the operation, if the 7-axis manipulator does not avoid collision with the obstacle using the redundant DOF, and then is capable of avoiding collision with the obstacle using all of the operating DOFs and the redundant DOE